Systems and methods for manufacturing semiconductor modules

ABSTRACT

A method for manufacturing semiconductor modules for image-sensing devices is disclosed. The method may comprise applying a removable layer on a first surface of a printed circuit board (PCB) which comprises a plurality of PCB units; mounting a photosensitive member to a second surface of each of the PCB units; and encapsulating the photosensitive member with an encapsulation layer on each PCB unit. Each PCB unit may comprise at least a semiconductor component on a second surface of the PCB and one or more opening across the first surface and the second surface. The photosensitive member and the removable layer separate the one or more opening from outside, and the photosensitive member is positioned to receive light through the opening. At least one semiconductor component is also encapsulated by the encapsulation layer on each PCB unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/617,843, filed Jun. 8, 2017, which claims priority to and benefit ofChinese Patent Application Nos. 201710353630.0 and 201710353700.2, bothfiled May 18, 2017, and 201710214886.3, 201710214887.8, 201720344605.1and 201710214811.5, all filed Apr. 1, 2017, the contents of all of whichare incorporated by reference in their entireties into the presentdisclosure.

TECHNICAL FIELD

The disclosure relates generally to systems and methods for preparingsemiconductor modules, particularly, semiconductor modules used inimage-sensing devices such as cameras in portable devices.

BACKGROUND

Image-sensing devices are widely used in electronic devices. Theimage-sensing devices need to be configured to fit in the electronicdevices, the design of which is often driven by consumer demands. Forinstance, for portable electronic devices, consumers prefer smallersizes without willing to accept sacrifice on capabilities and qualities.In particular, in the field of portable electronic devices such asmartphone and tablets, thinner devices are in general more attractivethan thicker ones.

Sometimes, the race to making thin devices causes the image-sensingdevice to protrude from the surface of an electronic device. This maynot only affect the appearance of the electronic device, but also renderthe image-sensing device susceptible to physical damages such asscratches or even breakages. Therefore, reducing the dimensions of animage-sensing device is of great importance. However, due to physics oflight, alteration of certain aspects of an image-sensing device isrestricted. For instance, in order to achieve certain specification, thedistance between an image sensor and the lens assembly may not beshortened.

An image-sensing device generally includes a circuit board, aphotosensitive member, semiconductor components, an optical lens or lensassembly, and a holder that mounts the other components on the circuitboard. In some designs, a filter is disposed between the lens and thephotosensitive member.

SUMMARY

One aspect of this disclosure is directed to a method for manufacturingsemiconductor modules for image-sensing devices. The method may compriseapplying a removable layer on a first surface of a printed circuit board(PCB) which comprises a plurality of PCB units; mounting aphotosensitive member to a second surface of each of the PCB units; andencapsulating the photosensitive member with an encapsulation layer oneach PCB unit. Each PCB unit may comprise at least a semiconductorcomponent on a second surface of the PCB and one or more openings acrossthe first surface and the second surface. The photosensitive member andthe removable layer separate the one or more openings from outside, andthe photosensitive member is positioned to receive light through theopening. At least one semiconductor component is also encapsulated bythe encapsulation layer on each PCB unit.

Another aspect of this disclosure is directed to a semiconductor modulewhich can be used in an imaging-sensing device. The module may comprisea printed circuit board (PCB); a removable layer on a first surface ofthe PCB; a photosensitive member; and an encapsulation layer. The PCBmay comprise at least a semiconductor component and one or more opening.At least one semiconductor component is positioned on a second surfaceof the PCB, one or more openings are across the first surface and thesecond surface, and are separated from outside by the photosensitivemember and the removable layer. The photosensitive member is positionedon the second surface of the PCB, and is configured to receive lightthrough the opening. The encapsulation layer is configured toencapsulate the photosensitive member and the at least one semiconductorcomponent with the PCB.

Another aspect of this disclosure is directed to an imaging-sensingdevice. The device may comprise one or more lens; a printed circuitboard (PCB); a transparent layer on a first surface of the PCB; aphotosensitive member; and an encapsulation layer. The PCB may compriseat least a semiconductor component and one or more openings. at leastone semiconductor component is positioned on the second surface of thePCB, one or more openings are across the first surface and the secondsurface, and are separated from outside by the photosensitive member andthe transparent layer. The photosensitive member is positioned on thesecond surface of the PCB, and is configured to receive light throughthe opening. The encapsulation layer is configured to encapsulate thephotosensitive member and the at least one semiconductor component withthe PCB.

It is to be understood that the foregoing general description and thefollowing detailed description are exemplary and explanatory only, andare not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which constitute a part of this disclosure,illustrate several non-limiting embodiments and, together with thedescription, serve to explain the disclosed principles.

FIG. 1 is graphical representation illustrating a structure of asemiconductor module, consistent with exemplary embodiments of thepresent disclosure.

FIG. 2 is a flow diagram illustrating a method for manufacturingsemiconductor modules for image-sensing devices; consistent withexemplary embodiments of the present disclosure.

FIG. 3(a) is a graphical representation illustrating a process forapplying a removable layer to a printed circuit board (PCB); FIG. 3(b)is a graphical representation illustrating an enlarged area of the PCB;consistent with exemplary embodiments of the present disclosure.

FIG. 4(a) is a side view of one exemplary embodiment of the PCB with theremovable layer; FIG. 4(b) is a side view of another exemplaryembodiment of the PCB with the removable layer; FIG. 4(c) is a side viewof another exemplary embodiment of the PCB with the removable layer;consistent with exemplary embodiments of the present disclosure.

FIG. 5(a) is a graphical representation illustrating a process formounting photosensitive members (e.g., image-sensing wafers); FIG. 5(b)is a side view of a PCB with photosensitive members; consistent withexemplary embodiments of the present disclosure.

FIG. 6(a)-(b) are graphical representations illustrating a process ofone embodiment, for encapsulating the semiconductor modules; FIG. 6(c)is a side view of a PCB with an encapsulation layer prepared by aprocess of another embodiment.

FIG. 7 is a flow diagram illustrating another method for manufacturingsemiconductor modules for image-sensing devices, consistent withexemplary embodiments of the present disclosure.

FIG. 8(a) is a side view of semiconductor modules with the removablelayer facing upward; FIG. 8(b) is a side view of a semiconductor modulewith the removable layer removed; consistent with exemplary embodimentsof the present disclosure.

FIG. 9 is a flow diagram illustrating a method for manufacturing animage-sensing device, consistent with exemplary embodiments of thepresent disclosure.

FIG. 10(a) is an exploded view of an image-sensing device; FIG. 10(b) isan exploded view of another image-sensing device; consistent withexemplary embodiments of the present disclosure.

FIG. 11 is a graphical representation illustrating a semiconductormodule having an encapsulation layer of a grid structure, consistentwith exemplary embodiments of the present disclosure.

FIG. 12 is a graphical representation illustrating an exemplaryapplication of an image-sensing device, consistent with exemplaryembodiments of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. The followingdescription refers to the accompanying drawings in which the samenumbers in different drawings represent the same or similar elementsunless otherwise represented. The implementations set forth in thefollowing description of exemplary embodiments consistent with thepresent invention do not represent all implementations consistent withthe invention. Instead, they are merely examples of systems and methodsconsistent with aspects related to the invention.

Introduction and Definitions

In some common designs of image-sensing devices, the photosensitivemember (e.g., image-sensing wafer) is mounted on the circuit board andthe semiconductor components are also mounted on the same side of thecircuit board. In order to prevent electric shortages and to accommodateall the semiconductor components, the surface of the circuit board needsto be sufficiently large.

It has also been observed that when the semiconductor components and thephotosensitive member are located in the same compartment, sheddingparticles of the semiconductor component due to contact or oxidation maycause contaminations to the photosensitive region of the photosensitivemember, or adhere to the filter element, resulting in defective images.

Another observation is that, during the manufacturing process, thephotosensitive member is exposed to the air and may collect dustparticles, which would compromise the quality of the device. In order toprevent collection of dust, the manufacturing process may need to becarried in a clean room, adding significant costs to the process.

Certain embodiments of the present disclosure provide systems andmethods for preparing image-sensing devices that are smaller in size andmore durable than what are currently available on the market, avoidingthe presence of dusts in the devices and reducing the cost of makingsuch devices.

In some embodiments, a process of manufacturing a semiconductor moduleis provided. In one embodiment, the circuit board is provided thatcontains or can be prepared to contain semiconductor components requiredby the semiconductor module. The circuit board, e.g., a printed circuitboard (PCB), can have a first surface that would face the lens assemblywhen assembled into an image-sensing device, hereinafter referred to asa “lens-facing surface.” The circuit board can also include an oppositesurface, hereinafter referred to as a “back surface.”

In some embodiments, a semiconductor component is disposed on the backsurface of the circuit board. In some embodiments, more than onesemiconductor components are disposed on the back surface. In someembodiments, the circuit board contains one “set” of semiconductorcomponents required for an image-sensing device. In some embodiments,the circuit board includes multiple sets, so that when the circuit boardis eventually divided into individual units, each unit can be assembledinto an image-sensing device. In this context, a portion of the circuitboard that includes a requisite set of the semiconductor component isreferred to as a “circuit board unit”, or “printed circuit board unit”(PCB unit).

It is noted, however, that an image-sensing device may include more thanone set of lens assembly-photosensitive member groups. For convenienceof annotation, if a group of lens-photosensitive member is referred toas a camera, then such image-sensing device may be referred to as havinga multi-camera array. In some embodiments, such an array includes twocameras. In some embodiments, such an array includes four cameras.

Also present, in each circuit board unit, is one or more openings. For acircuit board unit to be assembled into a single-camera device, theremay be one opening. For a circuit board unit to be assembled into amulti-camera device, there may be more than one opening. Each opening,in some embodiments, is shaped so that when a photosensitive member isfixed on one side of the circuit board, light can travel through theopening from the other side of the circuit board to arrive at thephotosensitive member. In some embodiments, the opening takes the shapeof round, rectangular, triangle, hexangular, or oval, withoutlimitation.

In some embodiments, in addition to the semiconductor componentsdisposed on the back surface of the circuit board, one or moresemiconductor components can also be disposed on the lens-facingsurface. In some embodiments, there are no semiconductor component onthe lens-facing surface. In some embodiments, there are fewersemiconductor components on the lens-facing surface than on the backsurface of the circuit board.

In the manufacturing process, in some embodiments, a removable layer anda photosensitive member can, at any order, be disposed on thelens-facing and back surfaces of the circuit board, respectively. In oneembodiment, the removable layer is disposed to the lens-facing surfaceof the circuit board first. In one embodiment, the photosensitive memberis disposed to the back surface of the circuit board first. In oneembodiment, both the removable layer and the photosensitive member aredisposed to the surfaces of the circuit board at the same time.

A “photosensitive member” as used herein refers to a semiconductormaterial having a substantively smooth surface which is sensitive tolight and can be configured to convert light to electric signals. Thesurface is commonly flat and the member typically comprises an electriccircuit on a wafer which is made of semiconducting materials withmethods readily known in the art.

A “removable layer” as used herein refers to any layer that can beapplied to cover openings of a surface of a board and provide insulationto the openings from dust particle contamination, and then be removedwhen needed. The removable layer may have an adhesive surface which,however, is not necessary. For instance, the removable layer can also befixed, temporarily, to the board by one or more clips or other physicalrestraints.

When each photosensitive member is installed, preferably the entire orthe majority of the photosensitive area of the photosensitive side isexposed through an opening of the circuit board. In one embodiment, oncethe photosensitive member is disposed on the back surface of thecircuit, the member seals the opening from the back surface to in a wayto prevent dust or other small particles from entering the opening fromthe side of the back surface. In one embodiment, the photosensitivemember itself does not seal the opening but a subsequent step will sealthe opening.

In some embodiments, each opening is mounted and sealed with aphotosensitive member. In some embodiments, the photosensitive member isnot in direct contact with any of the semiconductor component. In someembodiments, more than one openings are mounted and sealed with aphotosensitive member. In some embodiments, the semiconductor componentsand welding materials are insulated from the photosensitive member witha non-conductive material, which can be applied after the openings aresealed.

The removable layer is disposed on the opposite, lens-facing surface ofthe circuit board. As explained in further detail below, one of thefunctions of the removable layer is to seal the opening, in combinationwith the photosensitive member (or the photosensitive member togetherwith an encapsulation layer), such that dust particles do not come intothe opening and contaminate the photosensitive member before theremovable layer is removed later. Therefore, many different materials,such as a heat resistant tape, and methods can be used to accomplishthis goal, which are discussed later.

As introduced above, in some embodiments, an encapsulation layer can beused to encapsulate a photosensitive member to the circuit board.Preferably, the encapsulation layer also encapsulates and protects thesemiconductor components on the circuit board. Also as described infurther details later, various materials and methods can be used toimplement the encapsulation function.

At this point, each opening of the circuit board is separated from theexternal environment by the removable layer and the photosensitivemember. Such prepared circuit board can then be separated intoindividual units, which can be referred to as “semiconductor modules”and can be used to prepare image-sensing devices. Until the removablelayer is removed later, therefore, the photosensitive surface of thephotosensitive member, which is now located in the opening, is insulatedfrom the external environment.

The manufacturing processes of the above embodiments have a fewadvantages over the conventional technology.

First, the presently disclosed processes lead to greatly reducedcontamination to the photosensitive member or other parts of the device.In a conventional manufacturing process, the photosensitive surface ofthe photosensitive member may be directly exposed to the environment ofthe workshop. Such an exposure is necessarily associated with highlikelihoods of damage and contamination. By contrast, in variousembodiments of the present technology, an insulated space is formed thatprotects the photosensitive surface. Such a process, therefore,necessarily results in higher quality image-sensing devices and increaseoverall process yield.

Second, the semiconductor modules and devices made by variousembodiments of the present technology are also smaller in size than whatare made by the conventional methods. Rather than placing thephotosensitive member on the lens-facing side of the board, in variousembodiments of the present technology, the photosensitive member isplaced below the board. Because the distance between the optic lens andthe photosensitive surface, given a requisite specification, cannot beshorter than a minimum, positioning of the board between the lens andthe photosensitive member does not result in extending the depth of theimage-sensing device. Along the perpendicular dimension, because thesemiconductor components are disposed on the back surface of the circuitboard, they can be closer to the photosensitive member. In other words,the present technology can reduce the size of semiconductor module, aswell as image-sensing devices that include the semiconductor module,along the perpendicular dimension. In some embodiments, thesemiconductor components are distributed over both surfaces of thecircuit board, further allowing the circuit board, hence the overallimage-sensing device, to be smaller.

Third, the semiconductor modules and devices made by certain embodimentsof the present disclosure can also be more durable than what are made bythe conventional methods. In the conventional technology, modulecomponents may be fixed on the circuit board by soldering or resin. Forsuch designs, external vibrations may loosen the components or evencause them to fall off. In some embodiments of the present technology,an encapsulation layer is employed to encapsulate various components inthe board to ensure reliability and durability of the whole module ordevice.

Fourth, for an image-sensing device that includes two or moresemiconductor modules (e.g., a dual-lens camera assembly, or aquadruple-lens camera assembly), no separate frame is required to holdand support the modules as what is typically done in the conventionaltechnology. Instead, the encapsulation layer can provide adequatesupport and security to the semiconductor modules. In some embodiments,the semiconductor modules may be arranged in an array with each modulehaving a lens assembly and associated photosensitive members and circuitboards. The encapsulation layer may secure the lens assemblies,photosensitive members and module components, and enhance the structurestability of the image-sensing device.

EXAMPLE EMBODIMENTS

FIG. 1 is a graphical representation illustrating an examplesemiconductor module of the present disclosure that can be used in animage-sensing device, consistent with exemplary embodiments of thepresent disclosure. The module may comprise a number of components, someof which may be optional. In some embodiments, the module may includemany more components than those shown in FIG. 1 . However, it is notnecessary that all of these components be shown in order to disclose anillustrative embodiment.

As shown in FIG. 1 , the module may include a printed circuit board(PCB) 102 (an example of a circuit board), one or more semiconductorcomponent 101, a removable layer 103, an image-sensing wafer 104 (anexample of a photosensitive member), an encapsulation layer 105, one ormore openings 106, and one or more welding materials 107. The PCB 102may have a first surface, a second surface and one or more openings 106.The opening 106 is across the first surface and the second surface, andis separated from outside by the wafer 104 and the removable layer 103.The removable layer 103 is located on the first surface of the PCB 102,and a semiconductor component 101 is located on the second surface ofthe PCB 102. The wafer 104 is also located on the second surface of thePCB 102, with its image-sensing surface facing towards and receivinglight through the opening 106. The wafer 104 is configured to conductwith the PCB 102 by the welding materials 107. The encapsulation layer105 is configured to encapsulate the wafer 104 and the semiconductorcomponent 101 with the PCB 102, optionally with a sealing material.

FIG. 2 shows a flow diagram illustrating a method 100 for manufacturingsemiconductor modules for image-sensing devices, in accordance with oneexemplary embodiment of the present disclosure. The steps involved inthe method 100 can also be graphically represented in FIGS. 3-6 .

At step 110 in FIG. 2 , a removable layer is applied on a first surfaceof a PCB. This process can be illustrated in a graphical representationin FIG. 3(a). As shown in FIG. 3(a), a removable layer 3002 is appliedto a first surface of a PCB 3001. The PCB 3001 may include a pluralityof PCB units, and each of the PCB units may include one or moresemiconductor component and one or more opening. The semiconductorcomponent is located on a second surface of the PCB, and the opening isacross the first surface and the second surface. To have a clear view ofthe PCB unit, Area 1 is selected and enlarged in FIG. 3(b). As shown inFIG. 3(b), the PCB unit has one opening, and a plurality ofsemiconductor components on the second surface of the PCB unit. In someembodiments, the PCB unit may have more than one openings.

FIGS. 4(a)-(c) present different embodiments of a PCB applied with aremovable layer, in accordance to the exemplary embodiments in thisdisclosure. In some embodiments, the removable layer may be a wholepiece covering a plurality of PCB units. In some embodiments, theremovable layer may comprise a plurality of removable layer pieces. Inone embodiment, each removable layer piece may be applied on one PCBunit. In another embodiment, each removable layer piece may be appliedto cover one opening of the PCB. As shown in FIG. 4(a), one removablelayer 403 is applied on a first surface of two PCB units 402, and eachPCB unit 402 has one opening 404. Semiconductor components 401 arepositioned on a second surface of the two PCB units 402. FIG. 4(b) showstwo removable layer pieces 413 applied on a first surface of two PCBunits 412 respectively, and each PCB unit 412 has two openings 414.Semiconductor components 411 are positioned on a second surface of thetwo PCB units 412. FIG. 4(c) shows two removable layer pieces 423applied on a first surface of two PCB units 422 respectively, and eachPCB unit 422 has one opening 424. Semiconductor components 421 arepositioned on a second surface of the two PCB units 422.

At step 120 in FIG. 2 , an image-sensing wafer is mounted on a secondsurface of each of the PCB units. This process can be illustrated in agraphical representation in FIG. 5(a). FIG. 5(a) shows a PCB 522 whichincludes a plurality of PCB units. A removable layer 523 is on a firstsurface of the PCB 522, and one or more semiconductor component 521locates on a second surface of each of the PCB unit. An image-sensingwafer 524 is mounted to the second surface of each of the PCB unit. Theimage-sensing surface of the wafer 524 faces towards and receives lightthrough the opening 527 of each of the PCB unit. In addition, theremovable layer 523 and the wafer 524 separate the opening 527 fromoutside, and the removable layer 523 prevents the wafer 524 fromcontamination. To have a clear view of the wafer mounting, Area II isselected and enlarged. As shown in the enlarged Area II, the wafer 524may be mounted to the PCB 522 by welding materials 525, and the weldinggaps are insulated by glue sealing 526. FIG. 5(b) illustrates a sideview of the PCB units with the wafers mounted. In FIG. 5(b), the PCBunits have the semiconductor components 501, the PCB 502, the removablelayer 503 and the wafers 504.

At step 130 in FIG. 2 , an encapsulation layer is applied on a secondsurface of the PCB to encapsulate the wafer and the semiconductorcomponent on each of the PCB units. This process can be illustrated ingraphical representations in FIGS. 6(a)-(b) in accordance with oneexemplary embodiment of the present disclosure. As shown in FIG. 6(a),in some embodiments, a molding device 616 may be used at step 130. Themolding device 616 is placed on the second surface of the PCB 612,forming a space among the molding device 616, semiconductor component611, PCB 612 and wafer 614. An encapsulation material 615 is then filledin the space to form an encapsulation layer. In FIG. 6(b), the moldingdevice 626 is removed, and an encapsulation layer 625 is formed. Thewafer 624 and the semiconductor component 621 are encapsulated by theencapsulation layer 625 and the PCB 622. FIG. 6(c) also shows a sideview of an example of the PCB units with an encapsulation layer, inaccordance with one exemplary embodiment of the present disclosure. InFIG. 6(c), the PCB units have the semiconductor components 631, the PCB632, the removable layer 633, the wafers 634 and the encapsulation layer635.

In some embodiments, the encapsulation layer may also be formed by butnot limited to blow molding, powder metallurgy and sintering,compression molding, extrusion molding, laminating, reaction injectionmolding, matrix molding, rotational molding, spin casting, transfermolding, thermoforming, vacuum forming, etc.

In some embodiments, the removable layer is a heat resistant adhesive.The heat resistant adhesive refers to a type of adhesive that remainsstable at high temperatures.

In some embodiments, the removable layer may be a type of polymer. Thepolymer that can be used as the removable layer may includepolypropylene, polyethylene terephthalate, polyvinyl chloride,polyimide, polytetrafluoroethylene, etc.

In some embodiments, the removable layer may be glass, a photoresist ora pressure sensitive adhesive (PSA). A photoresist is a light-sensitivematerial that forms a coating on a surface. A positive photoresist is atype of photoresist in which the portion of the photoresist that isexposed to light becomes soluble to the photoresist developer. A PSA isadhesive which forms a bond when pressure is applied to marry theadhesive with the adherent. No solvent, water, or heat is needed toactivate the adhesive.

In some embodiments, the removable layer may comprise a plurality ofremovable layer pieces, and each piece is applied to each PCB unitseparately, or each piece is applied to cover each opening of the PCBseparately. Exemplary embodiments of the plurality of removable layerpieces are shown in FIGS. 4(b)-(c).

In some embodiments, the removable layer may be applied on the PCB bypressure, heat, chemical vapor deposition, clipping, plating or spaying.For example, a PSA can be pressed on the PCB as a removable layerwithout solvent, water, or heat to activate the adhesive. In anotherembodiment, a piece of glass can be clipped or glued onto the PCB as aremovable layer.

In some embodiments, the removable layer can be removed from the PCB bypeeling, for example, the removable layer comprises PSA. In someembodiments, the removable layer can be removed by dissolving in asolution. In some embodiments, the removable layer is a positivephotoresist, and can be removed by exposing to light and dissolving by aphotoresist developer.

In some embodiments, the encapsulation layer may comprise a polymer. Forexample, an epoxy molding compound (EMC) may be used as theencapsulation material. EMCs are widely used to encapsulatesemiconductor devices due to their superior properties such as highmechanical strength and high productivity. In some embodiments, EMCs aresolid epoxy polymers that are heated to a liquid and then injected intoa molding device to form protection. An exemplary embodiment with EMC asthe encapsulation material can be illustrated in FIGS. 6(a)-(b).

In some embodiments, the encapsulation layer may comprise polyvinylbutyral, a silicon, ceramics, or graphite.

In some embodiments, the encapsulation layer may be formed by a mixreaction, heating, or exposure to UV light.

FIG. 7 is a flow diagram illustrating a method 200 for manufacturingsemiconductor modules for image-sensing devices, consistent with anotherexemplary embodiment of the present disclosure. In addition to theprocess discussed previously in method 100, the method 200 may furtherinclude steps 220, 230, and 260.

Prior to mounting an image-sensing wafer to each of the PCB units, thewafer is cleaned at step 220 and mounted with welding materials at 230.The welding materials are used to conduct the wafer to the PCB units.The welding materials are graphically illustrated in as 525 in FIG. 5(a)in accordance with the exemplary embodiments of the present disclosure.At step 260, the PCB is divided into individual PCB units. As shown inFIG. 8(a), the PCB may include a plurality of PCB units. Each PCB unitmay include at least one semiconductor component 801, a piece of PCB802, a piece of removable layer 803, a wafer 804, and a piece of anencapsulation layer 805. In some embodiments, the PCB units are dividedwith a particular direction, so that the PCB unit may have an inclinededge 806, shown in FIG. 8(a). The inclined edge 806 may have an anglewith a range of 0.1-10°. By dividing the PCB into individual PCB units,each PCB unit may be a semiconductor module that can be used in animage-sensing device. As discussed previously, one example of thesemiconductor module is graphically illustrated in FIG. 1 .

In some embodiments, a process of flipping the PCB is performed to havethe image-sensing surface of the wafer changed from facing downward toupward. An exemplary embodiment with downward-facing wafers is shown inFIG. 5(b), and an exemplary embodiment with upward-facing wafers isshown in FIG. 8(a). With the image-sensing surface facing downwardduring the manufacturing process, the image-sensing surface is morelikely to be protected from contamination.

In one embodiment, the PCB is flipped before the PCB is divided intoindividual PCB units. In another embodiment, the PCB is divided intoindividual PCB units, then each PCB unit is then flipped to have theimage-sensing surface of the wafer changed from facing downward toupward.

In some embodiments, the removable layer is a heat resistant adhesive.The heat resistant adhesive refers to a type of adhesive that remainsstable at high temperatures.

In some embodiments, the removable layer may be a type of polymer. Thepolymer that can be used as the removable layer may includepolypropylene, polyethylene terephthalate, polyvinyl chloride,polyimide, polytetrafluoroethylene, etc.

In some embodiments, the removable layer may be glass, a photoresist ora pressure sensitive adhesive (PSA). A photoresist is a light-sensitivematerial that forms a coating on a surface. A positive photoresist is atype of photoresist in which the portion of the photoresist that isexposed to light becomes soluble to the photoresist developer. A PSA isadhesive which forms a bond when pressure is applied to marry theadhesive with the adherent. No solvent, water, or heat is needed toactivate the adhesive.

In some embodiments, the removable layer may comprise a plurality ofremovable layer pieces, and each piece is applied to each PCB unitseparately, or each piece is applied to cover each opening of the PCBseparately. Exemplary embodiments of the plurality of removable layerpieces are shown in FIGS. 4(b)-(c).

In some embodiments, the removable layer may be applied on the PCB bypressure, heat, chemical vapor deposition, clipping, plating or spaying.For example, a PSA can be pressed on the PCB as a removable layerwithout solvent, water, or heat to activate the adhesive. In anotherembodiment, a piece of glass can be clipped or glued onto the PCB as aremovable layer.

In some embodiments, the removable layer can be removed from the PCB bypeeling, for example, the removable layer comprises PSA. In someembodiments, the removable layer can be removed by dissolving in asolution. In some embodiments, the removable layer is a positivephotoresist, and can be removed by exposing to light and dissolving by aphotoresist developer.

In some embodiments, the encapsulation layer may comprise a polymer. Forexample, an epoxy molding compound (EMC) may be used as theencapsulation material. EMCs are widely used to encapsulatesemiconductor devices due to their superior properties such as highmechanical strength and high productivity. In some embodiments, EMCs aresolid epoxy polymers that are heated to a liquid and then injected intoa molding device to form protection. An exemplary embodiment with EMC asthe encapsulation material can be illustrated in FIGS. 6(a)-(b).

In some embodiments, the encapsulation layer may comprise polyvinylbutyral, a silicon, ceramics, or graphite.

In some embodiments, the encapsulation layer may be formed by a mixreaction, heating, or exposure to UV light.

FIG. 9 is a flow diagram illustrating a method 300 for manufacturing animage-sensing device, consistent with the exemplary embodiments of thepresent disclosure.

Similar to the previously discussed method 100, for the method 300, atstep 301, a removable layer is applied on a first surface of PCB. Atstep 302, an image-sensing wafer is mounted on a second surface of eachof the PCB units. At 303, an encapsulation layer is applied to a secondsurface of the PCB to encapsulate the wafer and the semiconductorcomponent on each of the PCB units.

At step 304, in FIG. 9 , the PCB is divided into individual PCB units.This process can be illustrated in a graphical representation in FIG.8(a) in accordance with one exemplary embodiment of the presentdisclosure. As shown in FIG. 8(a), the PCB may include a plurality ofPCB units. Each PCB unit may include at least one semiconductorcomponent 801, a piece of PCB 802, a piece of removable layer 803, awafer 804, and a piece of an encapsulation layer 805. In someembodiments, the PCB units are divided with a particular direction, sothat the PCB unit may have an inclined edge 806, shown in FIG. 8(a). Theinclined edge 806 may have an angle with a range of 0.1-10°. By dividingthe PCB into individual PCB units, each PCB unit may be a semiconductormodule that can be used in an image-sensing device. As discussedpreviously, one example of the semiconductor module is graphicallyillustrated in FIG. 1 .

At step 305, the removable layer can be removed. As shown in FIG. 8(b),a semiconductor module includes at least one semiconductor component811, a PCB 812, an image-sensing wafer 814 and an encapsulation layer815. The PCB 812 may have a first surface, a second surface, an inclinededge 816 and one or more opening 817. The opening 817 is across thefirst surface and the second surface, and is open for further processwith the removable layer removed. The semiconductor component 811 islocated on the second surface of the PCB 812. The wafer 814 is alsolocated on the second surface of the PCB 812, with its image-sensingsurface facing towards and receiving light through the opening 817. Theencapsulation layer 815 is configured to encapsulate the wafer 814 andthe semiconductor component 811 with the PCB 812.

At step 306, the PCB unit may be assembled with a lens assembly to forman image-sensing device. This process can be illustrated in a graphicalrepresentation in FIG. 10(a) in accordance with one exemplary embodimentof the present disclosure. As shown in FIG. 10(a), the PCB unit withouta removable layer, may include at least a PCB 1002, at least onesemiconductor component 1001, at least a wafer 1004 and an encapsulationlayer 1005. The PCB unit is assembled to a lens assembly 1007 to form animage-sensing device. In some embodiments, an image-sensing device mayalso include a transparent layer 1006 as shown in FIG. 10(a). Thetransparent layer 1006 is mounted between the image-sensing wafer 1004and the lens assembly 1007. It is positioned on the first layer of thePCB 1002, covering the opening of the PCB 1002 and leaving a space abovethe wafer 1004. In some embodiments, a frame or a molding is installedto support the transparent layer 1007.

In some embodiments, the removable layer is a heat resistant adhesive.The heat resistant adhesive refers to a type of adhesive that remainsstable at high temperatures.

In some embodiments, the removable layer may be a type of polymer. Thepolymer that can be used as the removable layer may includepolypropylene, polyethylene terephthalate, polyvinyl chloride,polyimide, polytetrafluoroethylene, etc.

In some embodiments, the removable layer may be glass, a photoresist ora pressure sensitive adhesive (PSA). A photoresist is a light-sensitivematerial that forms a coating on a surface. A positive photoresist is atype of photoresist in which the portion of the photoresist that isexposed to light becomes soluble to the photoresist developer. A PSA isadhesive which forms a bond when pressure is applied to marry theadhesive with the adherent. No solvent, water, or heat is needed toactivate the adhesive.

In some embodiments, the removable layer may comprise a plurality ofremovable layer pieces, and each piece is applied to each PCB unitseparately, or each piece is applied to cover each opening of the PCBseparately. Exemplary embodiments of the plurality of removable layerpieces are shown in FIGS. 4(b)-(c).

In some embodiments, the removable layer may be applied on the PCB bypressure, heat, chemical vapor deposition, clipping, plating or spaying.For example, a PSA can be pressed on the PCB as a removable layerwithout solvent, water, or heat to activate the adhesive. In anotherembodiment, a piece of glass can be clipped or glued onto the PCB as aremovable layer.

In some embodiments, the removable layer can be removed from the PCB bypeeling, for example, the removable layer comprises PSA. In someembodiments, the removable layer can be removed by dissolving in asolution. In some embodiments, the removable layer is a positivephotoresist, and can be removed by exposing to light and dissolving by aphotoresist developer.

In some embodiments, the encapsulation layer may comprise a polymer. Forexample, an epoxy molding compound (EMC) may be used as theencapsulation material. EMCs are widely used to encapsulatesemiconductor devices due to their superior properties such as highmechanical strength and high productivity. In some embodiments, EMCs aresolid epoxy polymers that are heated to a liquid and then injected intoa molding device to form protection. An exemplary embodiment with EMC asthe encapsulation material can be illustrated in FIGS. 6(a)-(b).

In some embodiments, the encapsulation layer may comprise polyvinylbutyral, a silicon, ceramics, or graphite.

In some embodiments, the encapsulation layer may be formed by a mixreaction, heating, or exposure to UV light.

FIG. 10(a) presents an exemplary embodiment of an image-sensing device.The device may include one or more lens, at least a PCB 1002, at leastone first semiconductor component 1001, at least an image-sensing wafer1004, an encapsulation layer 1005 and at least a transparent layer 1006.The PCB 1002 may have a first surface, a second surface and one or moreopening. The opening is across the first surface and the second surface,and is separated from outside by the wafer 1004 and the transparentlayer 1006. The transparent layer 1006 is located on the first surfaceof the PCB 1002, and the first semiconductor component 1001 is locatedon the second surface of the PCB 1002. In some embodiments, a frame or amolding is installed to support the transparent layer 1007. The wafer1004 is also located on the second surface of the PCB 1002, with itsimage-sensing surface facing towards and receiving light through theopening. The encapsulation layer 1005 is configured to encapsulate thewafer 1004 and the semiconductor component 1001 with the PCB 1002.

In some embodiments, as shown in FIG. 10(b), an image-sensing device mayinclude one or more lens, at least a PCB 1012, at least one firstsemiconductor component 1011, an image-sensing wafer 1024, a firstencapsulation layer 1015, a transparent layer 1016, at least one secondsemiconductor component 1011′ and a second encapsulation layer 1015′. Atleast one second semiconductor component 1011′ are positioned on thefirst surface of the PCB 1012. The second encapsulation layer 1015′ mayencapsulate the at least one second semiconductor component 1011′ andprevents the second semiconductor component 1011′ from contacting withthe transparent layer 1016. In some embodiments, the first encapsulationlayer 1015 and the second encapsulation layer 1015′ may comprise sameencapsulation material; in some embodiments, the first encapsulationlayer 1015 and the second encapsulation layer 1015′ may comprisedifferent encapsulation materials.

In some embodiments, the transparent layer may include a plurality oftransparent layer pieces, and each piece may be applied to each of theone or more opening separately. In some embodiments, the transparentlayer may comprise a polymer or glass. In some embodiments, thetransparent layer may be used as an optical filter.

In some embodiments, an image-sensing device may include a plurality ofsemiconductor modules which may be arranged to provide an array ofmodules each having a lens assembly and associated photosensitivemembers and PCBs. In some embodiment, the image-sensing device incudestwo semiconductor modules, each semiconductor module having lensassembly of different optical properties. In some embodiment, theimage-sensing device incudes four semiconductor modules, at least someof which semiconductor module having lens assembly of different opticalproperties.

In some embodiments, the encapsulation layer may have different shapesor structures, for example, rectangular, circular, elliptical, orirregular shapes. FIG. 11 shows an encapsulation layer having astructure of a grid with multiple recesses. The holes may work ascooling windows. The grid structure may provide an even support to thePCB to increase assembly strength, and spaces for accommodatingdifferent assembly structures.

In some embodiments, the image-sensing device may be implemented in amobile or stationary device which can take photos or videos. FIG. 12shows an exemplary embodiment of an imaging-sensing device implementedin a mobile phone. In some embodiments, the image-sensing device mayalso be implemented as but not limited to a tablet computer, anelectronic book, an MP3/4/5, a personal digital assistant, a camera, atelevision set, a washing machine, a car, a train, a plane etc.

In accordance with one embodiment of the present disclosure, therefore,provided is a method for manufacturing semiconductor modules forimage-sensing devices, comprising:

applying a removable layer on a first surface of a printed circuit board(PCB) comprising a plurality of PCB units, wherein each PCB unitcomprises at least a semiconductor component on a second surface of thePCB and one or more opening across the first surface and the secondsurface;

mounting an image-sensing wafer to the second surface of each of the PCBunits wherein the wafer and the removable layer separate the one or moreopening from outside, and the wafer is positioned to receive lightthrough the opening;

encapsulating the wafer and the at least one semiconductor componentwith an encapsulation layer on each PCB unit; and

dividing the PCB into individual PCB units.

In some embodiments, the method further comprises removing the removablelayer from a divided PCB unit; and assembling the unit into a lensassembly. In some embodiments, the method further comprises, prior tomounting the wafer to each of the PCB units: cleaning the wafer; andmounting welding materials on the wafer.

In some embodiments, the removable layer is a heat resistant adhesive.In some embodiments, the removable layer comprises a polymer. In someembodiments, the polymer comprises polypropylene, polyethyleneterephthalate, polyvinyl chloride, polyimide, orpolytetrafluoroethylene.

In some embodiments, the removable layer comprises glass, a positivephotoresist or a pressure sensitive adhesive. In some embodiments, theremovable layer comprises a plurality of removable layer pieces, andeach piece is applied to each PCB unit separately. In some embodiments,the removable layer is applied on the PCB by pressure, heat, chemicalvapor deposition, clipping, plating, or spraying. In some embodiments,the removable layer is removed from the PCB unit by peeling, a solution,or exposing to light and dissolving in a photoresist developer.

In some embodiments, the encapsulation layer comprises a polymer. Insome embodiments, the polymer comprises an epoxy molding compound. Insome embodiments, the encapsulation layer comprises polyvinyl butyral, asilicon, ceramics, or graphite. In some embodiments, the encapsulationlayer is formed by a mix reaction, heating, or exposure to UV light.

The present disclosure, in another embodiment, provides a semiconductormodule, comprising:

a printed circuit board (PCB) which comprises at least a semiconductorcomponent and one or more opening;

a removable layer on a first surface of the PCB;

an image-sensing wafer positioned on a second surface of the PCB toreceive light through the opening; and

an encapsulation layer configured to encapsulate the wafer and the atleast one semiconductor component with the PCB, wherein the at least onesemiconductor component is on the second surface of the PCB, the one ormore opening is across the first surface and the second surface, and isseparated from outside by the wafer and the removable layer.

In some embodiments, the removable layer is a heat resistant adhesive.In some embodiments, the removable layer comprises a polymer. In someembodiments, the polymer comprises polypropylene, polyethyleneterephthalate, polyvinyl chloride, polyimide, orpolytetrafluoroethylene.

In some embodiments, the removable layer comprises glass, a positivephotoresist or a pressure sensitive adhesive. In some embodiments, theremovable layer comprises a plurality of removable layer pieces, andeach piece is applied to each of the one or more opening separately.

In some embodiments, the encapsulation layer comprises a polymer. Insome embodiments, the polymer comprises an epoxy molding compound. Insome embodiments, the encapsulation layer comprises polyvinyl butyral, asilicon, ceramics, or graphite.

Also provided, in one embodiment, is an image-sensing device,comprising:

one or more lens;

a printed circuit board (PCB) which comprises at least one firstsemiconductor component and one or more opening across a first surfaceand a second surface of the PCB;

an image-sensing wafer; and

at least an encapsulation layer configured to encapsulate the wafer andat least one first semiconductor component with the PCB, wherein thewafer is positioned on the second surface of the PCB to receive lightthrough the opening, the at least one first semiconductor component ison the second surface of the PCB.

In some embodiments, image-sensing device further comprises at least atransparent layer disposed between the lens and the photosensitivemember, wherein the one or more opening is separated from the outside bythe photosensitive member and the transparent layer. In someembodiments, the transparent layer comprises a plurality of transparentlayer pieces, and each piece is applied to each of the one or moreopening separately. In some embodiments, the transparent layer comprisesa polymer or glass. In some embodiments, the transparent layer comprisesan optical filter.

In some embodiments, the encapsulation layer comprises a polymer. Insome embodiments, the polymer comprises an epoxy molding compound. Insome embodiments, the encapsulation layer comprises polyvinyl butyral, asilicon, ceramics, or graphite.

In some embodiments, the device further comprises at least one secondsemiconductor component positioned on the first surface of the PCB.

In some embodiments, the device further comprises a support for thetransparent layer. In some embodiments, the device further compriseswelding materials that weld the photosensitive member to the PCB. Insome embodiments, the device further comprises insulation glue thatseals gaps between the welding materials and the photosensitive member.In some embodiments, the encapsulation layer has an inclined edge withan angle of 0.1-10°. In some embodiments, the encapsulation layercontacts with the photosensitive member, and has an inner contactingsurface with an inclination of 10-80°. In some embodiments, theencapsulation layer contacts with the PCB, and has an outer contactingsurface with an inclination of 5-45°.

In some embodiments, the device further comprises the image-sensingdevice is enclosed in an electric device that further comprises at leasta processor and a storage.

The invention described and claimed herein is not to be limited in scopeby the specific preferred embodiments disclosed herein, as theseembodiments are intended as illustrations of several aspects of theinvention. Indeed, various modifications of the invention in addition tothose shown and described herein will become apparent to those skilledin the art from the foregoing description. Such modifications are alsointended to fall within the scope of the appended claims.

What is claimed is:
 1. A method for manufacturing semiconductor modulesfor image-sensing devices, comprising: applying a removable layer on afirst surface of a printed circuit board (PCB) comprising a plurality ofPCB units, wherein each PCB unit comprises at least a semiconductorcomponent on a second surface of the PCB and one or more openings acrossthe first surface and the second surface of the PCB; mounting at least aphotosensitive member to the second surface of each of the PCB units viawelding materials, wherein a first surface of the photosensitive memberand the removable layer separate the one or more openings from anambient environment, and the first surface of the photosensitive memberis positioned to receive light through the one or more openings, whereinthe one or more openings span a distance between a first PCB unit and asecond PCB unit, a length of the photosensitive member exceeds a lengthof the one or more openings, and the photosensitive member extends froma first end of the first PCB unit to a second end of the second PCBunit; insulating gaps between the welding materials and thephotosensitive member via a glue sealing to prevent dust from contactingthe photosensitive member; and encapsulating the photosensitive memberand at least one semiconductor component with an encapsulation layer oneach PCB unit, wherein the encapsulating layer is in direct contact witha second surface of the photosensitive member and seals the secondsurface of the photosensitive member and the at least one semiconductorcomponent from the ambient environment, and the second surface of thephotosensitive member is opposite to the first surface of thephotosensitive member.
 2. The method of claim 1, further comprisingremoving the removable layer from a divided PCB unit.
 3. The method ofclaim 1, further comprising assembling the unit into a lens assembly. 4.The method of claim 1, further comprising, prior to mounting thephotosensitive member to each of the PCB units, cleaning thephotosensitive member and mounting welding materials on thephotosensitive member.
 5. The method of claim 1, wherein the removablelayer is a heat resistant adhesive or comprises a polymer.
 6. The methodof claim 5, wherein the polymer comprises polypropylene, polyethyleneterephthalate, polyvinyl chloride, polyimide, orpolytetrafluoroethylene.
 7. The method of claim 1, wherein the removablelayer comprises glass, a positive photoresist or a pressure sensitiveadhesive.
 8. The method of claim 1, wherein the removable layer isapplied on the PCB by pressure, heat, chemical vapor deposition,clipping, plating, or spraying.
 9. The method of claim 1, wherein theremovable layer is removed from the PCB unit by peeling, grinding, asolution, or exposing to light and dissolving in a photoresistdeveloper.
 10. The method of claim 1, wherein the encapsulation layercomprises a polymer.
 11. The method of claim 10, wherein the polymercomprises a molding compound.
 12. The method of claim 1, wherein theencapsulation layer comprises polyvinyl butyral, a silicon, ceramics, orgraphite.
 13. The method of claim 1, wherein the encapsulation layer isformed by a mix reaction, heating, cooling, or exposure to UV light. 14.A semiconductor module, comprising: at least a printed circuit board(PCB) which comprises at least a semiconductor component and one or moreopenings; at least a removable layer on a first surface of the PCB; atleast a photosensitive member positioned on a second surface of the PCB,wherein a first surface of the photosensitive member is configured toreceive light through the one or more openings; and an encapsulationlayer configured to encapsulate the photosensitive member and the atleast one semiconductor component with the PCB, wherein: at least onesemiconductor component is on the second surface of the PCB, the one ormore openings are across the first surface and the second surface of thePCB, and are separated from an ambient environment by the photosensitivemember and the removable layer, the photosensitive member is mounted tothe second surface of the PCB by welding materials, gaps between thewelding materials and the photosensitive member are insulated by a gluesealing to prevent dust from contacting the photosensitive member, theone or more openings span a distance between a first PCB unit and asecond PCB unit, and the photosensitive member extends from a first endof the first PCB unit to a second end of the second PCB unit, thewelding materials extend past the second end of the second PCB unit, afirst end of the photosensitive member contacts the welding materials,and the glue sealing extends past the first end of the photosensitivemember, and the encapsulating layer is in direct contact with a secondsurface of the photosensitive member and seals the second surface of thephotosensitive member and the at least one semiconductor component fromthe ambient environment, and the second surface of the photosensitivemember is opposite to the first surface of the photosensitive member.15. The semiconductor module of claim 14, wherein the removable layer isa heat resistant adhesive.
 16. The semiconductor module of claim 14,wherein the removable layer comprises glass, a positive photoresist or apressure sensitive adhesive.
 17. An image-sensing device, comprising:one or more lens; at least a printed circuit board (PCB) which comprisesat least one semiconductor component and one or more openings across afirst surface and a second surface of the PCB; at least a photosensitivemember; and at least an encapsulation layer configured to encapsulatethe photosensitive member and the at least one semiconductor componentwith the PCB, wherein: the photosensitive member is positioned on thesecond surface of the PCB and attached via welding materials, gapsbetween the welding materials and the photosensitive member areinsulated via a glue sealing to prevent dust from contacting thephotosensitive member, a first surface of the photosensitive member isconfigured to receive light through the one or more openings, the atleast one semiconductor component is on the second surface of the PCB,the at least one semiconductor component comprises at least a firstsemiconductor component and a second semiconductor component, the one ormore openings span a distance between the first semiconductor componentand the second semiconductor component, a length of the photosensitivemember exceeds a length of the one or more openings, and thephotosensitive member extends from a first end of the firstsemiconductor component to a second end of the second semiconductorcomponent, and the encapsulating layer is in direct contact with asecond surface of the photosensitive member and seals the second surfaceof the photosensitive member and the at least one semiconductorcomponent from an ambient environment, and the second surface of thephotosensitive member is opposite to the first surface of thephotosensitive member.
 18. The image-sensing device of claim 17, furthercomprising at least a transparent layer disposed between the lens andthe photosensitive member, wherein the one or more openings areseparated from the ambient environment by the photosensitive member andthe transparent layer.